WASHINGTON – There are $40 billion worth of unused gift cards out there, just waiting for people to take advantage of them.

They are cards long-forgotten in the bottom of the sock drawer, or bought from a store where you never shop.

But they are not worthless and you can still get something out of them.

There are number of options according to Odysseas Papadimitriou, chief executive officer of CardHub.com.

You can regift them, even if they look used, by going to the store from which they.

“You essentially ask them to switch them with a brand new gift card and usually they are happy to do so,” says Papadimitriou.

You also can sell them online at CardHub, though he recommends sellers and buyers meet in person in a public place to actually make the deal.

For online buyers, the gift cards are often sold at discounts.

If you are buying a gift card for someone, Papadimitriou recommends you be aware of his favorite stores and buy a store gift card. Those cards usually do not come with hidden fees that can eat up the value of a card if it is not used right away.

Gift cards with a Visa or Master Card logo can be used almost anywhere, but they do come with fees that are often hidden.

Gift cards are now a $100 billion a year business, and Papadimitriou says they are now the most requested holiday gift because of their flexibility.